It is native to much of Africa, Asia (Brunei Darussalam, China, India, Japan, Korea, and the Philippines) and parts of Australia.

[5] The plant reproduces vegetatively when branches break off the main axis, or sexually when sporocarps on the leaves release spores.

[6] It is present in New Zealand as an introduced species and an invasive weed that has crowded out a native relative, Azolla rubra.

[7] The weevil Stenopelmus rufinasus is used as an agent of biological pest control to manage Azolla filiculoides, and it has been found to attack A. pinnata as well.

A. pinnata was primarily studied due to its high tolerance to environmental pollutants, and ability to hyperaccumulate heavy metals.

[18] Phytoremediation of industrial wastewater containing heavy metals (such as zinc, lead,[19] chromium,[20] mercury, cadmium,[21] copper, arsenic[18]) as well as organic dyes such as methyl violet 2B[22] and malachite green[23] are reported in literature.